Floor drain with built-in sediment trap and removable gas trap

ABSTRACT

The present invention comprises a floor drain with built-in sediment trap for solids and removable gas trap assembly ( 403 ) for trapping of gasses. The lid ( 406 ), optional basket ( 402 ), and gas trap assembly ( 403 ) are removable by hand. Gas trap assembly ( 403 ) is designed to be self aligning on the exit pipe ( 405 ) within the drainage bowl ( 417 ) and of sufficient weight to remain effective throughout the gas “push-through” process.

FIELD OF THE INVENTION

The present invention generally relates to floor drain assemblies. Thepresent invention is broadly concerned with an improved floor drainassemblies of the type used in industrial plants such as dairies, cheeseplants, beverage, meat packing, canning, chemical, pharmaceutical,packaging plants and warehouses and in institutions such as laboratoriesand hospitals. The present invention is adapted for use in any locationthat has a concern with sewer gasses and germs and liquid bornecontaminants More particularly, the invention pertains to such drainassemblies which include, beneath the drain inlet, a unique removablegas trap assembly operable to retain gases, such as sewer gas, within anexit pipe while allowing liquids and waste material, save for the smallamount that serves as a aqueous barrier, to drain into the exit pipe.The exemplary embodiment of the present invention is cylindrical inshape and made of stainless steel, but can be any number of shapes andmaterial and still achieve its technical advantages.

BACKGROUND OF THE INVENTION

Large industrial operations such as dairies, cheese plants, beverage,meat packing, canning, chemical, pharmaceutical, packaging plants andwarehouses are faced with severe drainage problems. Similar issues arisein institutions such as laboratories and hospitals. The aqueous wastefrom such plants contains a high percentage of particulates of varioussizes which must be discharged into the sanitary sewer system. Thedrainage system must address two concerns. First, the particulate-ladenwaste must be handled without clogging. Moreover, drain assemblies mustbe designed to prevent or at least minimize the escape of sewer gasesand microorganisms from the sewage system back into the plant. Forexample, Lysteria contamination from floor drains is a concern at manymeat packing houses.

Conventional drainage systems typically have a p-trap installed, oftenas dictated by applicable plumbing codes. Traps maintain a liquidbarrier between the sewage system and the interior plumbing of abuilding. Without a trap to seal off plumbing fixtures, sewer gases,such as explosive methane gas can find their way into a building.19th-century plumbing systems often failed to have traps, and theresulting smell was the first notification that a dwelling had indoorplumbing.

Conventional gooseneck-type drain assemblies have proven to betroublesome in the context of industrial applications. These assembliesare prone to clogging, and they are susceptible to significantmicroorganism contamination. Furthermore, they are difficult todisassemble for maintenance and cleaning purposes. There is accordinglya need for an improved floor drain assembly, especially designed forindustrial applications in order to handle large volumes ofparticulate-laden waste streams and still obtain the objectives ofminimizing the escape of sewer gas and simple disassembly.

SUMMARY OF THE INVENTION

The present invention achieves advantages as a floor drain with built-insediment trap for solids and removable gas trap assembly for trapping ofgasses. The lid, optional basket, and gas trap assembly of the presentinvention are removable by hand. In one embodiment of the presentinvention the gas trap assembly is designed to be self aligning on theexit pipe within the drainage bowl and of sufficient weight to remaineffective throughout the gas trapping process.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention, reference ismade to the following detailed description taken in conjunction with theaccompanying drawings wherein:

FIG. 1 is an illustration of the disassembled parts of a conventionalfloor drain assembly;

FIG. 2 is a side view illustration of a conventional floor drainassembly showing the trap;

FIG. 3 is a front perspective view of a conventional floor drainassembly;

FIG. 4 is a cutaway side view of the present invention showing thevarious components and drainage flow;

FIG. 5 is a view looking downward into one embodiment of the drainassembly of the present invention without the gas trap assembly orbasket;

FIG. 6 is a second view looking downward into the drain assembly of thepresent invention without the gas trap assembly or basket;

FIG. 7 is a perspective view of the drain assembly of the presentinvention with the gas trap assembly, basket and lid nearby;

FIG. 8 is a top perspective view of the gas trap assembly of the presentinvention;

FIG. 9 is a bottom perspective view of the gas trap assembly of thepresent invention;

FIG. 10 is a top view of the drain assembly of the present inventionwith the gas trap assembly located therein; and

FIG. 11 is a top view of the drain assembly of the present inventionwith the gas trap assembly and basket located therein; and

FIG. 12 is a top view of the drain assembly of the present inventionwith the gas trap assembly and basket located therein and the lid placedthereon.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is an illustration of the disassembled parts of a conventionalfloor drain assembly made of a plastic or polypropylene material.

FIG. 2 is a side view illustration of a conventional floor drainassembly showing trap 201. As seen in FIG. 2, the trap 201 of drainageis the curved section of drain line that prevents sewer odors fromescaping into the atmosphere. Disadvantageously, the trap 201 is fixedin position and cannot be easily removed to unclog the drain or toengage in maintenance.

FIG. 3 is a front perspective view of a conventional floor drainassembly that has not been installed in a floor. The conventional drainassembly has a lid 301 with holes for liquids to flow and a trap 302that serves as a aqueous barrier to gas.

FIG. 4 is a cutaway side view of the present invention showing thevarious components thereof and the drainage flow path. As seen therein,the present invention comprises a main housing 401, whose inner walldefines drainage bowl 417, and a gas trap assembly 403. Optionally, abasket 402 to catch larger particulate matter can be placed upon the gastrap assembly 403 within drainage bowl 417. In the embodiment thatincludes the basket 402, the drainage path 410 of substantially all ofthe aqueous matter entering from the outer environment 423 into thedrainage bowl 417 is through the basket 402, around the impervious outertop wall 414 and impervious outer lateral wall 416 of the gas trapassembly 403 into the inner cavity comprised of inner lateral wall 415and inner top wall 412 of the gas trap assembly 403 and into exit pipe405. Lid 406 is made to fit snugly within lip 409 so as to keep it fromfalling into drainage bowl 417. In addition, the main housing 401 of thepresent invention can be adapted to existing trench drains easier andmore effectively

As can be seen in the exemplary embodiment, the main housing 401 has aradius (r) and lateral length (h) and is sunk into the floor 407 so asto create the substantially cylindrical drainage bowl 417 in the floor407 with a volume of approximately pi*r*r*h. A preferred shape of themain housing 401, optional basket 402 and gas trap assembly 403 arecylindrical. Round shapes are less likely to promote bacteria growthwhereas corners as found in parallelepipeds and prisms are breedinggrounds for bacteria. Furthermore, round shapes are less likely to causecracks in adjacent flooring materials, Nevertheless, if a non-circulardrain shape is required, the main housing, gas trap assembly could beparallelepiped or prism and still covered within the scope of thepresent invention.

FIG. 5 is a view looking downward into one embodiment of the drainassembly of the present invention without the gas trap assembly 403 orbasket 402. FIG. 6 is a second view looking downward into the drainassembly of the present invention without the gas trap assembly 403 orbasket 402. As seen in FIGS. 5 and 6, exit pipe 405 extends into thedrainage bowl 417 through aperture 418 in the bottom 408 of the mainhousing 401. The diameter of the aperture 418 is just slightly largerthan that of the diameter of exit pipe 405 so as to allow a tight fitbetween the two. A seal or other impervious material can be added,welded or coupled between the outside lateral wall of exit pipe 405 andthe aperture 418 at their point of contact so as to keep liquids fromseeping between the two. As noted in FIG. 4, exit pipe 405 is an opencylinder that extends into main housing drainage bowl 417, and gas trapassembly 403 is a closed cylinder. The diameter of gas trap assembly403, including its extensions 801 (as seen in FIG. 8), is less than thediameter of the main housing 401 so as to permit the gas trap assembly403 to be freely inserted into the main housing 401 when the lateralside walls of each are parallel. The diameter of the exit pipe 405 isless than the diameter of the inner lateral wall 415 of gas trapassembly 403 so as to permit the open end of the gas trap assembly 403to be inserted over the exit pipe 405 when the lateral side walls ofeach are parallel.

Referring back to FIG. 4, gas trap assembly 403 is adapted to bepositioned such that the closed end of gas trap assembly 403 is placedover the terminal end of exit pipe 405 that extends into drainage bowl417. A set of members, referred to as inner fins 411, are attached, byweld in one embodiment, perpendicular to the inner lateral walls 415 andorthogonal to the inner top wall 412 of gas trap assembly 403. The innerfins 411 sit on top of the annular shaped terminal end 421 of exit pipe405 and define a passageway between the inner lateral wall 415 and innertop wall 412 of gas trap assembly 403 and outer lateral wall of exitpipe 405. One skilled in the art would recognize that there are avariety of configurations that are operable to keep the trap elevatedabove the exit pipe and such alternative configurations are encompassedwith the present invention. For example, tabs can be fabricated on topof the exit pipe versus on the bottom of the trap, and tabs of anothershape, such as round stock, long tabs or extensions on the trap canextend all of the way to the bottom of the bowl.

When viewing the cutaway side view of the main housing 401, exit pipe405 and gas trap assembly 403, of FIG. 4, it can be seen that when gastrap assembly 403 is seated over and on exit pipe 405, there is a length419 of the lateral wall 415 of gas trap assembly 403 that extends belowthe terminal end 421 of exit pipe 405. This length extension 419,coupled with the passageway defined by the terminal open end 422 of gastrap assembly 403 and the bottom wall 408 of main housing 401, withlength 420, allow aqueous matter to flow along the drainage path 410into exit pipe 405 while also forming an aqueous barrier 404 between theexit pipe 405 and the outer environment 423.

FIG. 7 is a perspective view of the drainage assembly of the presentinvention with the gas trap assembly 403, optional basket 402 and lid406 nearby. As seen in FIG. 7, the lid 406, optional basket 402, and gastrap assembly 403 are advantageously removable from the drainage bowl417 defined by main housing 401, by hand.

FIG. 8 is a top perspective view of the gas trap assembly 403 of thepresent invention. Optional members, referred to as outer fins 413,serve to support optional basket 402 and to define a passageway foraqueous material between basket 402 and around impervious outer top wall414 and impervious outer lateral wall 416 of gas trap assembly 403. Oneskilled in the art would recognize that there are a variety of memberconfigurations operable to support optional basket 402 and suchalternative member configurations are encompassed with the presentinvention. For example tabs can extend down from the bottom of thebasket.

Handle 802 can be used to remove gas trap assembly 403 from the drainagebowl 417 defined by main housing 401 by hand. Any number of variationsof the handle can be made and still fall within the scope of the presentinvention.

FIG. 9 is a bottom perspective view of the gas trap assembly 403 of thepresent invention showing the inner lateral wall 415, inner top wall 412and inner fins 411. As seen in FIGS. 4, 8 and 9, gas trap assembly 403is designed to be self aligning and of sufficient weight to remaineffective throughout the gas push-through process. In other words, thegas pressure required to push the column of water 404 in the gas trapassembly 403 up and “bubble” into the environment is less than the gaspressure required to lift the gas trap assembly. One skilled in the artwould recognize that there are a variety of means for keeping gas trapassembly 403 aligned and secured to prevent gas push through and suchalternative means are encompassed with the present invention. Forexample the gas trap assembly can be secured by using the weight of thebasket to hold it down, or mechanically fastening it with a fastener,such as a screw or bolt, or by physically holding it in place by a“twist-to lock” method wherein tabs sticking out from the trap assemblyfit into grooves on the inside of the bowl and then the trap is twistedto “lock” it onto place.

Referring back to FIG. 4, inner fins 413 are attached inside, andperpendicular to, the cylindrical inner lateral wall 415 and inner topwall 412. In one embodiment, inner fins 413 are welded to the inner wall415 and inner top wall 412. Edges 901 of inner fins 413 rest upon theterminal end 421 of exit pipe 405. FIG. 10 is a top view of the drainassembly of the present invention with the gas trap assembly 403 andbasket located therein.

FIG. 11 is a top view of the drain assembly of the present inventionwith the gas trap assembly 403 and optional basket 402 located therein.

FIG. 12 is a top view of the drainage assembly of the present inventionwith the gas trap assembly 403, optional basket 402 located therein andlid 406 placed thereon.

As can be seen from the Figures and discussion herein, the presentinvention achieves a variety of advantages over conventional drainassemblies. No tools are required to disassemble and remove the gas trapassembly 403, optional basket 402 and lid 406 from the drainage bowl 417of the present invention. The use of the present invention thus cancontribute significantly to the cleanliness and hygiene at food plantsand at institutions such as laboratories and hospitals. The presentinvention is less likely to clog up than standard p-trap drains becausethe sedimentation area and the gas drain are visible and accessible.Also, if the sediment trap does get full and clogs, then the sedimentcan be visually seen and physically removed before it enters theunderground plumbing systems where it can cause other problems. Becausethe gas trap is removable, a plumber can expose the main drain line toperform maintenance. This reduces manufacturing downtime. The novel handremovable gas trap assembly 403 and removable optional basket 402 permitimproved access to the drain for cleaning. As such, the presentinvention allows clogs to be cleared faster and with proper maintenance,can substantially prevent clogs from occurring. Furthermore, theoptional basket can be customized and easily swapped to catch differentsizes of particulate matter. One skilled in the art would recognize thatthe present invention can be fabricated in a variety of sizes anddimensions and such alternative sizes and dimensions are encompassedwith the present invention. For example main housing drainage bowl 417can be oversized to create a larger sediment trap. Also, the heights ofdrainage path 410 and inner fins 411 can be changed to increase ordecrease the “effective trap height” which effects the gas trap'seffectiveness. In other word, the length of length extension 419 can bevaried to increase or decrease the amount of pressure required toovercome the trap thus increasing or decreasing the effectiveness of thetrap.

In one embodiment of the present invention, the lid 406, main housing401, optional basket 402 and gas trap assembly 403 are made of 304stainless steel. Stainless steel is a preferred material as it isresistant to acid, corrosion and staining. However, other materials,such as heavy duty cast iron bodies and high-grade nickel-bronze can beused to fabricate the present invention, The gas trap assembly 403 canbe made of any material as long as the gas trap has enough mass toresist being lifted by the gas pressure, or is otherwise configured soas to resist the gas pressure through, for example, the use of twist-onor lock mechanisms. These gas trap assembly 403 materials include castiron, metal alloys, including stainless steel, polyvinyl chloride (pvc)ABS or related polymer or plastic. The gas trap minimum weight iscalculated based on the dimensions of the drain. For example, a 4 inchdrain and a 6 inch drain may have different requirements. One gas trapassembly 403 in an embodiment of the present invention weighsapproximately fifteen (15) pounds. The drain is further designed to beforklift rated, meaning a standard forklifts can drive over it withoutdamaging the drain. Furthermore, lid 406 can be a standard stainlesssteel plate cover with holes, or can comprise a bar type grating.Furthermore, the steel plate cover can have a grate design that useslettering, holes or different shaped apertures.

The numerous innovative teachings of the present invention are describedwith particular reference to an exemplary embodiment of a main housingand removable gas trap assembly made of stainless steel and both havinga cylindrical shape. However, it should be understood that the exemplaryembodiment is only one example of the many advantageous embodiments andinnovative teachings herein. In general, statements made in thespecification of the application do not necessarily delimit any of thevarious claimed inventions. For example, a drain according to theinvention may be designed with a variety of dimensions. Moreover, somestatements may apply to some inventive features, but not to others.Detailed descriptions of known functions and constructions unnecessarilyobscuring the subject matter of the present invention have been omittedfor clarity. The present invention is also described in terms of variousfunctional components. It should be appreciated that such functionalcomponents may be realized by any number of hardware or structuralcomponents configured to perform the specified functions. For example,the present invention may be comprised in a number of shapes or made ofa variety of materials. Additionally, the various components may beimplemented in alternate ways, such as, for example, with or without asediment trap or strainer basket. These alternatives can be suitablyselected depending upon the particular application or in considerationof any number of factors associated with the operation of the drain orthe location of the drain. Such general applications that may beappreciated by those skilled in the art in light of the presentdisclosure are not described in detail herein. These and other changesor modifications are intended to be included within the scope of thepresent invention, as expressed in the following claims.

1. A drain assembly, comprising: a drainage bowl; an inlet to thedrainage bowl; the drainage bowl having a bottom wall and an aperturethrough the bottom wall thereof; an exit pipe extending into theaperture on the bottom wall of the drainage bowl with a terminal endending within the drainage bowl; a gas trap assembly; the gas trapassembly having a first end, a second end and one or a plurality ofperpendicular side walls so as to form a volume therein, a top wallcovering the first end, the second end being open; the gas trap assemblyhaving members located within the first end of its inner volume,attached perpendicular to the side walls and orthogonal to the top wall;the gas trap assembly being adapted to be placed within the drainagebowl; the gas trap assembly being adapted to be placed with the innertop wall over the terminal end of the exit pipe; the members within theinner volume of the gas trap assembly being positioned over andcontacting the terminal end of the exit pipe; the relative location ofthe inner top wall and side walls of the gas trap assembly to the outerwall and terminal end of the exit pipe defining a passageway from thedrainage bowl into the exit pipe for conveying waste materials; and thepassageway formed by the relative location of the inner top wall andside walls of the gas trap assembly to the outer wall and terminal endof the exit pipe operable to create an aqueous barrier when aqueousmatter is sent through the passageway.
 2. The drain assembly of claim 1,further comprising when the gas trap assembly is seated over and on theexit pipe there is a length of the lateral wall of the gas trap assemblythat extends below the terminal end of exit pipe, said configurationallowing aqueous matter to flow along a drainage path into the exit pipewhile also forming the aqueous barrier between the exit pipe and theouter environment.
 3. The drain assembly of claim 1, further comprisinga main housing defining the drainage bowl.
 4. The drain assembly ofclaim 3, further comprising: the main housing, gas trap assembly andexit pipe being cylindrical in shape; the main housing having a diametergreater than the diameter of the gas trap assembly; and the gas trapassembly having a diameter greater than the exit pipe.
 5. The drainassembly of claim 3, further comprising a sediment basket adapted to bepositioned on top of the gas trap assembly within the drainage bowl. 6.The drain assembly of claim 3, further comprising the main housing andgas trap assembly being made of stainless steel.
 7. The drain assemblyof claim 3, further comprising the gas trap assembly being made of castiron.
 8. The drain assembly of claim 3, further comprising the gas trapassembly being made of a metallic material.
 9. The drain assembly ofclaim 3, further comprising the gas trap assembly being made of ametallic material.
 10. The drain assembly of claim 3, further comprisingthe gas trap assembly being made of a pvc, plastic or ABS type material.11. The drain assembly of claim 3, further comprising the main housingbeing made of a metallic material.
 12. The drain assembly of claim 3,further comprising the main housing being made of a pvc, plastic or ABStype material.
 13. The drain assembly of claim 3, wherein the gas trapassembly is adapted to self align on the exit pipe within the drainagebowl.
 14. The drain assembly of claim 3, wherein the gas trap assemblyis of sufficient weight to remain effective throughout the gas“push-through” process.
 15. The drain assembly of claim 3, wherein thegas trap assembly has a means of being secured in place throughout thegas “push-through” process.
 16. The drain assembly of claim 3, whereinthe means by which the gas trap assembly remains secured in placecomprises a twist-to-lock mechanism.
 17. The drain assembly of claim 3,wherein the gas trap assembly has a handle coupled to the top of theouter wall of the top end.
 18. The drain assembly of claim 1, whereinthe gas trap assembly is of sufficient weight to remain effectivethroughout the gas “push-through” process.
 19. A floor drain assembly,comprising: a drainage bowl; an inlet to the drainage bowl locatedadjacent the level of said floor and an outlet below said inlet; thedrainage bowl having a bottom wall and an aperture through the bottomwall thereof; an exit pipe extending from the subfloor into the apertureon the bottom wall of the drainage bowl with a terminal end within thedrainage bowl; a gas trap assembly; the gas trap assembly having a firstend, a second end and one or a plurality of perpendicular side walls soas to form a volume therein, a top wall covering the first end, thesecond end being open; the gas trap assembly having members locatedwithin the first end of its inner volume, attached perpendicular to theside walls and orthogonal to the top wall; the gas trap assembly beingadapted to be placed with the first end up over the exit pipe; themembers within the inner volume of the gas trap assembly beingpositioned over and contacting the terminal end of the exit pipe; therelative location of the inner top wall and side walls of the gas trapassembly to the outer wall and terminal end of the exit pipe defining apassageway from the drainage bowl into the exit pipe for conveying wastematerials from a floor to a subfloor drain; and the passageway formed bythe relative location of the inner top wall and side walls of the gastrap assembly to the outer wall and terminal end of the exit pipeoperable to create an aqueous barrier when aqueous matter is sentthrough the passageway.
 20. A drain assembly, comprising: a drainagebowl; an inlet to the drainage bowl; the drainage bowl having a bottomwall and an aperture through the bottom wall thereof; an exit pipeextending into the aperture on the bottom wall of the drainage bowl witha terminal end ending within the drainage bowl; a gas trap assembly; thegas trap assembly having a first end, a second end and one or aplurality of perpendicular side walls so as to form a volume therein, atop wall covering the first end, the second end being open; the gas trapassembly being adapted to be placed within the drainage bowl; the gastrap assembly having a means for being supported over the terminal endof the exit pipe; the members within the inner volume of the gas trapassembly being positioned over and contacting the terminal end of theexit pipe; the relative location of the inner top wall and side walls ofthe gas trap assembly to the outer wall and terminal end of the exitpipe defining a passageway from the drainage bowl into the exit pipe forconveying waste materials; and the passageway formed by the relativelocation of the inner top wall and side walls of the gas trap assemblyto the outer wall and terminal end of the exit pipe operable to createan aqueous barrier when aqueous matter is sent through the passageway.21. The floor drain assembly of claim 20, further comprising when thegas trap assembly is seated over and on the exit pipe there is a lengthof the lateral wall of the gas trap assembly that extends below theterminal end of exit pipe, said configuration allowing aqueous matter toflow along a drainage path into the exit pipe while also forming theaqueous barrier between the exit pipe and the outer environment.
 22. Thefloor drain assembly of claim 20, further comprising a main housingdefining the drainage bowl.
 23. The floor drain assembly of claim 22,further comprising: the main housing, gas trap assembly and exit pipebeing cylindrical in shape; the main housing having a diameter greaterthan the diameter of the gas trap assembly; and the gas trap assemblyhaving a diameter greater than the exit pipe.
 24. The floor drainassembly of claim 22, further comprising a sediment basket adapted to bepositioned on top of the gas trap assembly within the drainage bowl. 25.The floor drain assembly of claim 22, further comprising the mainhousing, sediment basket and gas trap assembly being made of stainlesssteel.
 26. The floor drain assembly of claim 22, further comprising themain housing and gas trap assembly being made substantially of stainlesssteel.
 27. The floor drain assembly of claim 20, further comprising thegas trap assembly being made substantially of cast iron.
 28. The floordrain assembly of claim 20, further comprising the gas trap assemblybeing made substantially of a metal alloy.
 29. The floor drain assemblyof claim 20, further comprising the gas trap assembly being madesubstantially of plastic, ABS or pvc based material.
 30. The floor drainassembly of claim 20, further comprising the gas assembly being made ofa combination of metal and pvc type material.
 31. The floor drainassembly of claim 20, wherein the gas trap assembly is adapted to selfalign on the exit pipe within the drainage bowl.
 32. The floor drainassembly of claim 20, wherein the gas trap assembly is of sufficientweight to remain effective throughout the gas “push-through” process.33. The floor drain assembly of claim 20, further comprising the gastrap assembly having a means of remaining secure throughout the gas“push-through” process.
 34. The floor drain assembly of claim 33,wherein the means by which the gas trap assembly remains securethroughout the gas “push-through” process comprises a twist-on lockmechanism.
 35. The floor drain assembly of claim 20, wherein the gastrap assembly has a handle coupled to the top of the outer wall of thetop end.
 36. A gas trap assembly, comprising: a first end; a second end;one or a plurality of side walls coupled between the first end andsecond end; the first end having a top wall covering; the second endbeing open; the first end, second end and coupled side wall(s) formingan void therewithin; and the gas trap assembly being adapted to bepositioned such that the closed end of the gas trap assembly can bepositioned over the terminal end of an exit pipe so as to define apassageway for waste material and form an aqueous barrier between theexit pipe and the first end of the gas trap assembly.
 37. The gas trapassembly of claim 36, further comprising being substantially cylindricalin shape.
 38. The gas trap assembly of claim 36, further comprisingbeing made substantially of a metal alloy.
 39. The gas trap assembly ofclaim 36, further comprising being made substantially of stainlesssteel.
 40. The gas trap assembly of claim 36, further comprising beingmade substantially of cast iron.
 41. The gas trap assembly of claim 36,further comprising having a set of members, attached perpendicular tothe inner lateral walls and orthogonal to the inner top wall of gas thetrap assembly; and the members being adapted to sit on top an exit pipeand define a passageway between the inner lateral wall and inner topwall of the gas trap assembly and outer lateral wall(s) of the exitpipe.
 42. The gas trap assembly of claim 36, further comprising when thegas trap assembly is seated over and on the exit pipe there is a lengthof the lateral wall of the gas trap assembly that extends below theterminal end of exit pipe, said configuration adapted to allow aqueousmatter to flow along a drainage path into exit pipe while also formingthe aqueous barrier between the exit pipe and the outer environment.